Republican presidential hopefuls are meeting on the debate stage for the second time in as many weeks, but that doesn't mean they'll be rehashing the same issues as last time.

From protests over racial incidents at the University of Missouri to a court ruling against President Obama's immigration actions to newfound scrutiny of Ben Carson, there will be plenty to talk about.

Here's a primer on nine of the top issues expected at Tuesday's fourth GOP presidential debate.

1. The media's role in debates

GOP Enemy No. 1 right now isn't President Obama or Hillary Clinton. It's the mainstream media, which Republican presidential candidates on stage in October's CNBC accused of treating them unfairly when moderators asked them supposed "gotcha" questions and were accused of picking fights. One of the race's front-runners, Carson, extended his battle with the media last week by claiming he's being scrutinized more than any other candidate, after CNN, Politico and the Wall Street Journal raised questions about how honest he's been about his rags-to-riches story.

Even without all this recent history, bashing the media is often a crowd-pleaser for GOP candidates. And GOP candidates banded together last time to get some formatting rules changed for this debate. But Fox Business moderators Maria Bartiromo and Neil Cavuto have given no indication they'll back off asking tough questions. "Be careful about looking like whiners and babies," warned Cavuto in an interview with The Fix's Callum Borchers.

2. Carson's past

Many candidates have had their moment under the magnifying class this election season — Donald Trump's business deals, Florida Sen. Marco Rubio's finances and traffic tickets, Carly Fiorina's time as head of Hewlett-Packard, and what really led to the economic recovery when former Florida governor Jeb Bush was governor of Florida, for example.

Now one of the race's current front-runners, retired neurosurgeon Ben Carson, is having to defend his past. CNN raised questions in a story about whether Carson did indeed suffer violent episodes of anger as a Detroit teen that led to him attempting to stab someone and hurl a hammer at his mother's head. (Carson still maintains he did.) Politico then reported that Carson was not offered a scholarship to the U.S. Military Academy at West Point, a critical juncture in Carson's personal narrative that helped steer him onto a path of redemption that eventually led to him becoming a world-renowned neurosurgeon. On Friday afternoon, Carson's campaign admitted that there was no formal scholarship offer from West Point but said the reporting oversold the discrepancy.

Carson comes into Tuesday's debate needing to convince voters he's being honest about his past and is trustworthy as a candidate. The good news? At least according to a new Washington Post-ABC News poll (taken before the full brunt of scrutiny about his past), he's still the most popular GOP candidate by far. And he's also pretty popular among independents.

3. The War on Christmas

Starbucks decides to ditch the decorative holiday stencils on its cups in favor of plain red ones; Donald Trump calls for a boycott of Starbucks. (And a lot of other things, actually.)

"No more 'Merry Christmas' at Starbucks. No more," Trump said at a rally in Iowa on Monday night as the crowd booed, according to The Post's Jenna Johnson.

The War on Christmas is a Christian conservative favorite rallying point, and there are no shortage of candidates on stage Tuesday hustling for the base's vote.

Expect candidates to bring up incidents like last year, when there was a backlash in a wealthy suburb of Washington, D.C., when the county school district decided to cut holiday names — Christmas, Easter, Yom Kippur, Rosh Hashanah — from its school calendar.

The War on Christmas is also low-hanging fruit in a debate about political correctness. Like denouncing an allegedly biased or lazy media, announcing that hyper-vigilant political correctness is contributing to America's decline is a GOP debate surety. Trump has been the most vocal opponent of PC-ness; in the party's first debate, he brushed off a potentially damaging question about some of Trump's most misogynistic comments and tweets by saying: "I don’t frankly have time for total political correctness. And to be honest with you, this country doesn't have time either."

But expect just about any candidate looking for an applause line to mention PC's blight on society. Trump just made it more topical.

4. Immigration

A federal court once again dealt Obama's immigration plans a blow. On Monday night,  the U.S. Court of Appeals for the 5th Circuit in New Orleans ruled 2 to 1 to uphold a lower court's injunction blocking the Obama administration from implementing executive action the president announced nearly one year ago. Obama wants to extend a program he announced in 2012 to defer deportations to millions more undocumented immigrants.

Republican presidential candidates want to dismantle it and say the president's attempt to alter immigration laws on his own undermines the separation of powers.

But immigration reform supporters aren't defeated yet; the court's ruling gives the Obama administration just enough time to file a case to the Supreme Court in the hopes the court will hear it next year and decide to okay his executive actions by June — just months before Obama leaves office. On Tuesday afternoon, his administration said it'll do just that.

5. Racial tensions at the University of Missouri

It's a story that mixes the negotiating power of college football, 1st Amendment rights of student journalists and questions about systemic racism on some college campuses. The drama stemming from race-related protests and the subsequent stepping down of the president and chancellor at the University of Missouri this week lends itself to no shortage of debate topics Tuesday.

A quick rundown of the news so far:

On Monday, the University of Missouri chancellor and president resigned after complaints by students they weren't doing enough to address racism in the school. The president, Tim Wolfe, wasn't happy about it, though:

"This is not — I repeat not — the way change should come about," he said. "Change comes from listening, learning, caring and conversation. We have to respect each other enough to stop yelling at each other and start listening, and quit intimidating each other. "

Their resignation came weeks after escalating protests by students, including one student's hunger strike, and a threatened strike by players on Missouri's football team, which alone would have cost the school more than $1 million had it forfeited its Saturday game against Brigham Young University.

Then on Tuesday, a University of Missouri assistant communications professor of mass media was widely criticized after being filmed recruiting "muscle" to stop a student photographer from filming a protest in a public space on campus.

Considering the potent mix of race, media and higher education, Republican presidential candidates have largely stayed out of it all. But there could certainly be questions about it Tuesday night.

6. Jobs and the economy

The debate's official focus is jobs and the economy — a trickier issue for Republicans to address than it might seem.

Unlike the 2012 campaign, when a sluggish economy was a potential drag on Obama's reelection hopes, Republicans are having a harder time pointing their finger at Obama's economy. The U.S. jobs market has almost fully healed from the depths of the Great Recession, according to jobs numbers out on Friday, reports The Post's Ylan Q. Mui. The October unemployment rate stands at 5 percent, and the economy added 271,000 jobs in October, the highest so far this year. In July, Democrats were touting 64 straight months of private-sector job growth under the president (although that's slowed with poorer-than-expected job numbers recently).

Some economists (and many Republican politicians) will note that the better-than-average unemployment rate is in large part because many people have stopped looking for work and aren't counted in the workforce. The labor force participation rate keeps dropping and now stands at 62.4 percent — down from over 66 percent before the recession.

It's enough of a concern that Bush has vocally criticized Obama's "zombie economy." Bush, who says he'll engineer an ambitious 4 percent annual GDP growth in office, likes to claim Florida led the nation in job growth while he was governor. But it's a statement The Washington Post's Fact Checker team rated as "bogus."

Other executives' claims of job growth, such as Kasich saying he took Ohio from an $8 billion hole to an economic surplus, have also come under scrutiny from The Post's Fact Checker team, which urges readers "to be wary about job-creation claims, either at the state or national level, as so much of what happens in an economy is beyond a politician’s control."

This won't stop those claims from being bandied about Tuesday night, of course.

7. Income inequality

Trump has called for ending tax breaks for the wealthy, such as the carried-interest exemption that allows some hedge-fund managers and venture capitalists to pay a lower tax rate than average Americans. Bush has said that some banks are too big. Sen. Rand Paul (Ky.) wants to end monetary policy that favors the wealthy.

In a moment where two-thirds of Americans (68 percent) believe our economic system favors the wealthy rather than being fair — including about half of Republicans, according to a July Washington Post/ABC News poll — the Republican party finds itself these days talking about income inequality almost as much as Democrats. And Trump's increasing populist bent makes this particularly timely.

8. Obamacare

The GOP is reinvigorated to focus on Obamacare after a big victory in the Kentucky governor's race last week. (The party took back the governor's mansion in a race that focused on whether to continue the Medicaid expansion under the health-care law. Democrats were counting on the Republican candidate's opposition to this as their silver bullet.)

Americans have been able to buy health insurance on state- and federally-run private exchanges since October 2013, when the hallmark piece of the president's 2010 health-care law, officially known as the Affordable Care Act, went into effect. Federal figures announced in September show that the number of uninsured in America has fallen after the law was implemented.

Meanwhile, the GOP-controlled House of Representatives has voted at least 50 times to defund or repeal the law and/or parts of it. But the law has not been struck down by the Supreme Court. In June, the Supreme Court handed down its second decision on the law, ruling 6 to 3 that federal tax credits for low-income Americans to buy insurance were legal. The court previously ruled 5 to 4 in 2012 to uphold the law's mandate that most Americans be insured or risk a financial penalty.

There are varying degrees of resignation when it comes to how ingrained the law is now and how Republicans should deal with a potential alternative, should they win the White House in 2016.

9. The Islamic State

For the past year, the United States and its allies have ramped up targeted airstrikes over Iraq and Syria to disrupt the terrorist group that calls itself the Islamic State. On Oct. 30, Obama announced that he planned to send 50 special operations forces to Syria, a pretty-clear reversal of his past promises to keep boots off the ground.

Republican presidential candidates panned the move, although their criticisms were all over the map, from being "too little, too late," according to Carly Fiorina, to a sign of weakness, according to Sen. Lindsey Graham (R-S.C.).

Obama faces increasing urgency to act. The Islamic State has beheaded many foreigners, including two American journalists, and controls an estimated one-third of the region. Americans are also trying to train Syrian and Iraqi fighters to battle the Islamic State on the ground. Pentagon officials have recently described this fight against the Islamic State as "a stalemate."

Politically, there is momentum in Republican circles for a more involved U.S. presence — up to and including ground troops. This has not been uniformly embraced by the candidates, though, as Republicans recall the war-weariness that marked the drawdowns in Iraq and Afghanistan.